Label-free multimodal nonlinear optical microscopy for biomedical applications
Guan‐Yu Zhuo, K U Spandana, Sindhoora Kaniyala Melanthota, Yury V. Kistenev, Fu‐Jen Kao, Viktor V. Nikolaev, Hala Zuhayri, Н. А. Кривова, Nirmal Mazumder
Abstract
This paper addresses the application of multimodal nonlinear optical (MNLO) microscopy to clinical research within the context of label-free non-invasive molecular imaging. Here, a compact MNLO microscope based on a laser scanning microscope, a femtosecond laser, a time-correlated single-photon counting system, and a photonic crystal fiber are introduced for biomedical applications. By integrating two-photon fluorescence, two-photon fluorescence lifetime imaging, second-harmonic generation, and coherent anti-Stokes Raman scattering microscopy, the proposed scheme provides profound insights into the physicochemical properties related to 3D molecular orientation distribution, inter- and intra-molecular interactions, and disease progression in biological systems and organs. The high peak power and the low average intensity of near-infrared laser pulses allow for deep-penetration imaging without compromising sample vitality. Linking nonlinear optical phenomena with time/spectral/polarization-resolved imaging also makes it possible to obtain multidimensional information to address complex biomedical questions.